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Spongy Moth

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E. Bradford Walker, Vermont Department of Forests, Parks and Recreation,

Bugwood.org

Spongy moth (Lymantria dispar dispar) is a destructive, invasive insect that poses a

danger to North America's forests. The caterpillars feed on the leaves of more than

300 species of trees and shrubs, eventually killing them. Female moths lay eggs on
many outdoor surfaces—stacked firewood, trailers, grills, lawn furniture, and toys.

When people move these items to a new location, the spongy moth's eggs also

move.

Native to Europe, the spongy moth first arrived in the United States well over a

century ago. Today it can be found throughout the Northeastern United States

where it has dramatically changed the landscape. Early detection is critical to limit

the spongy moth's spread to new areas. If left unchecked, this pest can strip leaves

and even kill trees, if severe defoliation persists for multiple seasons.

What To Look For

Egg masses (late summer, winter and spring)

Female moths attach egg masses to trees, stones, walls, logs, and

household items, such as patio furniture, children’s toys, and lawn

equipment.

Each egg mass contains up to 1,000 eggs and is covered with buff or

yellowish “hair” (from the abdomen of the female).

Egg masses are about 1-1/2 inches long and 3/4-inch wide on average.

Caterpillars (spring)

Newly hatched caterpillars are black and hairy.

Older caterpillars are a mottled yellow to gray color with tufts of bristle-like

hairs. They also have a distinctive color pattern along their backs with five

pairs of blue dots followed by six pairs of red dots.

They are about 1-1/2 to 2-1/2 inches long when fully grown.

Adult moths (summer)

Male moths are brown with a darker brown pattern on their wings and

have a 1-1/2-inch wingspan.

Females are nearly white, slightly larger, and have a 2-inch wingspan but

do not fly. Their wings are marked with dark, saw-toothed patterns.

Defoliated trees

Infested trees may be partially or completely bare of leaves.

A heavily infested forest will have a barren, wintry look in the middle of the

summer.
View photos of spongy moth and the damage it causes:

Tap any image to view larger size.







Show Info

1st instar larva emerging from egg mass. USDA Photo.

Spongy Moth Pupae. Photo by PA Department of Conservation and Natural

Resources-Forestry Archive, Bugwood.org

Spongy Moth Larva. USDA Photo by John H. Ghent, Forest Service, Bugwood.org

Female spongy moths laying egg masses. Photo by Milan Pernek, Forestry Research

Institute, Bugwood.org

Defoliation, Photo by Haruta Ovidiu, University of Oradea, Bugwood.org

Defoliated oak branch, Photo by Louis-Michel Nageleisen, Département de la Santé

des Forêts, Bugwood.org

Adult Male Spongy Moth, USDA Photo by John H. Ghent, Forest Service



How To Prevent This Pest

The spongy moth is a hitchhiker. People can unknowingly spread this pest when they

move vehicles and other outdoor items that have spongy moth egg masses

attached. Here's what you can do to prevent spongy moth from spreading:

Look for spongy moth egg masses on trees, lawn furniture, fences, walls,

outdoor items, and report them to Federal or State agriculture officials if you

are not in a quarantine area.

Know and follow any quarantines regulations in your area, especially if you are

relocating. Check the Regulatory Information panel below for more information.

Before moving or traveling out of an infested area, check for the spongy moth

egg masses, caterpillars and adults. This is required by Federal law in many

areas. See details below under "Your Move Spongy Moth-Free."

Buy local firewood and burn it on site. Do not move firewood.  

Comply with Federal, State, and local spongy moth restrictions.

Cooperate with agriculture officials surveying for this pest. They may ask for

access to your property to place and check insect-monitoring traps.

Your Move Spongy Moth-Free

Per USDA requirements, you must inspect and remove spongy moth egg masses

from household goods before moving from a location within a spongy moth
quarantine area to a location outside the quarantine area.

You may face penalties if you are required to inspect but fail to do so. Fortunately,

it's easy to meet the requirements:

1. Check the map to find out whether you live in a quarantine area.

2. Look for spongy moth egg masses and other life stages (see above photos) on

all outdoor household items.

Use and print the self-inspection checklist (2.85 MB) or the online checklist

option.

If you're moving between April and August, complete the inspection on

moving day, if possible.  

If you cannot complete the inspection on moving day, you must protect

the items from infestation. Seal them under a tarp or keep them indoors or

in a closed moving truck.

3. Remove and destroy any egg masses or life stages you find.

Scrape them off with a putty knife, stiff brush, or similar hand tool.

Dispose of egg masses and other life stages in a container of hot, soapy

water, or place them in a plastic bag, seal it, and set it in the sun.

4. Check each item off on your checklist (2.85 MB) as you go and complete the

requested information.

If a qualified certified applicator performs the inspection, be sure you get a

copy of the completed, signed checklist.

5. Keep a copy of the completed checklist in the vehicle moving the goods. This is

your official certificate of inspection. USDA or State officials may request it

during your trip.

If you are not driving, provide a copy to the driver. 

Note: If you do not live in a quarantine area, this law does not apply to you.

Questions? Contact your State plant regulatory official or State plant health director.

How It Is Treated

Homeowners in spongy moth quarantine areas can contact their county Extension

office to ask about spongy moth control options. Individuals in non-quarantine areas,

should contact their State plant health director or State plant regulatory official to
report spongy moth.

Report Plant Pests and Diseases

Have you seen this pest or signs of pest damage? Immediately report your findings.

Find your State plant regulatory official

Find your State plant health director

Controlling Spongy Moth

Current Status

Spongy moth is currently found in Connecticut, Delaware, the District of Columbia,

Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, New

Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island,

Vermont, Virginia, West Virginia, and Wisconsin.

Host trees are everywhere, and all States are at high risk for spongy moth. People

can spread the pest when they move regulated articles (134.24 KB), such as patio

furniture, lawn equipment, outdoor play toys, grills, trailers, and vehicles, from the

quarantine area.

Federal Spongy Moth Quarantine Interactive Map

List of Quarantine Areas (171.41 KB)

APHIS' Response

Through quarantines and an active regulatory program, APHIS works with State

departments of agriculture, U.S. Forest Service, and other cooperators to define the

extent of the spongy moth infestation, eradicate isolated populations, and regulate

the human-assisted spread of the pest beyond the infested area. Our effective

partnerships have successfully limited the spread of spongy moth.

Regulatory Information

Spongy Moth Regulated Areas (171.41 KB)

Spongy Moth Regulated Articles (134.24 KB)
Code of Federal Regulations

7 CFR Part 301

Federal Orders

August 8, 2023, APHIS Adds Lake and Whitley Counties, Indiana to the Spongy

Moth (Lymantria dispar) Quarantine Area (171.68 KB)

April 10, 2023, APHIS Adds Douglas County, Wisconsin to the Spongy Moth (

Lymantria dispar) Quarantine Area (144.95 KB)  

May 28, 2014, APHIS Removes a Condition of Movement for Certain Articles

Regulated for Gypsy Moth (19.27 KB)

Information for Cooperators

USDA Spongy Moth Program Manual (3.98 MB)

USDA Forest Service Slow the Spread Project

Slow the Spread Foundation Website

An Analysis of the Economic Feasibility of the Spongy Moth Slow the

Spread Project

National Slow the Spread Program Story Map

Flighted Spongy Moth Complex

(Lymantria dispar asiatica, L. d. japonica, L. albescens, L. umbrosa, and L. postalba)

The life stages of the flighted spongy moth complex (FSMC) look and behave almost

identically to spongy moth life stages. One difference is that FSMC adult females can

fly and spread rapidly if left unchecked. Also, this pest is not established in the

United States.

We periodically detect these pests on ships arriving at U.S. ports from countries

where they are known to occur. Their egg masses tolerate temperature and

moisture, and travel well on the hulls and rigging of ocean-going ships, shipping

containers, and pallets.

To mitigate the pest risk, APHIS and the Canadian Food Inspection Agency (CFIA)

work with China, Japan, South Korea, and Russia to inspect and certify that ships

headed for North America are free of flighted spongy moth complex before they
leave Asia. When ships arrive here, APHIS inspects them for flighted spongy moth

complex. We also periodically survey general and high-risk areas to detect any

possible introductions in the United States.

If we confirm a flighted spongy moth complex detection in the United States, we will

work with other Federal and State agencies to evaluate the infestation and take

actions to eradicate the pest.

Flighted Spongy Moth Complex Survey and Response Guidelines (1.12 MB)

Spread the Word

USDA has created a number of outreach materials to help its partners, which include

moving companies and associations, environmental groups and advocates, and

government agencies, to spread the word about the spongy moth. With this toolkit,

our partners can reach out to people moving or traveling out of an infested area and

explain the steps they can take to protect America's forests and comply with Federal

law. The partner toolkit elements are free and can be downloaded with the links

below.

Distribute or post a link to our checklist “It's the Law: Before Moving, Check for

the Spongy Moth” (3.6 MB).

Provide the list of quarantined counties (171.41 KB) to their customers or

stakeholder.

Link to USDA's interactive spongy moth quarantine map.

Reports and Assessments

View All Final Environmental Documents

Record of Decision, Gypsy Moth Management in the United States: A

Cooperative Approach (83.46 KB)

Contact Us

Kathryn Bronsky

National Policy Manager
Email: kathryn.e.bronsky@usda.gov

Phone: 301-851-2147